def recvall(sock: socket.socket, n: int) -> bytearray:
'''Receive exactly n bytes from a socket.'''
buf = bytearray(n)
view = memoryview(buf)
ptr = 0
while ptr < n:
count = sock.recv_into(view[ptr:])
if count == 0:
raise IOError('Premature end of stream')
ptr += count
return buf
def read_or_eof(sock: socket, count: int) -> bytes:
b = bytearray(count)
view = memoryview(b)
while count:
nbytes = sock.recv_into(view, count)
if nbytes == 0:
raise EOFError()
view = view[nbytes:]
count -= nbytes
return bytes(b)
